7.62x39

yes just get a cutting torch and cut where you want, dress with a file and to recrown just use a drill bit thats bigger than the hole but woller a lot when you do you may have to touch up the place where you cut it

A hack saw will work. It's best to press a bullet in the bore at the point of the cut. Cutting through the bullet will help keep the chrome from flaking which isn't a big deal anyway. Use the heaviest .311" bullet you can find. The length will help insure the bullet is at the point of the cut. Also can measure inside and out to line up everything.